Let's get this math done. We have 512 and we're going to multiply it by 4. This is the same as taking 512 and adding it to itself 4 times.
Step 1: 0 + 512 = 512
Step 2: 512 + 512 = 1024
Step 3: 1024 + 512 = 1536
Step 4: 1536 + 512 = 2048

So, 512*4 = 2048